Lubricant compositions

ABSTRACT

Water-soluble salts (e.g., alkali metal, ammonium or watersoluble amine salts) of styrene-maleic anhydride copolymer halfesters are employed in aqueous solutions as coolants and lubricants for metal-working operations e.g., metal cutting and abrading. The copolymers are esterified with both a fatty alcohol having from 10 to 22 carbon atoms and a lower alkoxy polyethylene glycol. Metal-working lubricant compositions are also formulated which comprise these salts along with extreme pressure agents such as amine salts of fatty acids and organic phosphate esters. Other additives may also be employed in the lubricating compositions of this invention.

United States Patent [15] 3,657,123 [4 1 Apr. 18, 1972 Stram [541LUBRICANT COMPOSITIONS [72] Inventor: Michael A. Strum, Chicago, Ill.

[73] Assignee: Atlantic Richileld Company, New York,

[22] Filed: Mar. 23, 1970 [21] Appl.No.: 21,993

[52] U.S.Cl. ..252/34.7, 252/34, 252/41, 252/42], 252/493, 252/495 [51]lnt.Cl. ..Cl0rn1l28 [58] Field olSearch ..252/34.7,421,493,495,

[56] Relerences Cited UNITED STATES PATENTS 2,285,853 6/1942 Downing etal ..252/34.7 X

2,753,305 7/1956 Whitbeck 2,999,064 9/1961 Sluhan 3,472,772 10/1969Chambers etal ..252/34.7

3,527,726 9/1970 Goweret al. ..252/49.3

Primary Examiner-Daniel E. Wyman Assistant ExaminerW. CannonAttorney-Morton, Bernard, Brown, Roberts & Sutherland, John \V.Behringer, James N. Dresser, Eugene L. Bernard, W. Brown Morton, Jr.,Thomas J. Clough, Martin J. Brown, John T. Roberts and Malcolm L.Sutherland [57] ABSTRACT Water-soluble salts (e.g., alkali metal,ammonium or watersoluble amine salts) of styrene-maleic anhydridecopolymer half-esters are employed in aqueous solutions as coolants andlubricants for metal-working operations e.g., metal cutting andabrading. The copolymers are esterified with both a fatty alcohol havingfrom 10 to 22 carbon atoms and a lower alkoxy polyethylene glycol.Metal-working lubricant compositions are also formulated which comprisethese salts along with extreme pressure agents such as amine salts offatty acids and organic phosphate esters. Other additives may also beemployed in the lubricating compositions of this invention.

20 Claims, No Drawings LUBRICANT COMPOSITIONS This invention isconcerned with novel watenbased coolants and lubricants for use inmetal-working operations. More specifically, this invention is directedto aqueous solutions of water-soluble alkali metal, ammonium or aminesalts of styrene-maleic anhydride copolymer esters, the copolymershaving been esterified with both a fatty alcohol having from 10 to 22carbon atoms and a lower alkoxy polyethylene glycol, which can beemployed in aqueous solution as aqueous, metal working lubricants andpreferably as metal cutting and abrading lubricants. This invention isalso concerned with aqueous lubricating compositions comprising thesewater-soluble salts of styrene-maleic anhydride copolymer esters, water,and extreme pressure (E?) agents.

Lubricants suitable for use in metal fabrication such as in cutting,abrading, threading, tapping and the like must effectively cool andlubricate both the tool and the worked metal. During such operations anenormous amount of heat is generated at the interface of the tool andwork piece which must be quickly dissipated in order to prevent damageeither the tool or work piece or both. This is accomplished by floodingthe interface with a fluid having a high capacity for heat absorption aswell as eflective lubricating properties for reducing friction betweenthe tool and work piece. The lubricants especially formulated for thesepurposes are known in the art as cutting fluids or cutting oils. Manycutting oils, especially the earliest fonns thereof, consist essentiallyof an emulsion of a mineral lubricating oil in water. While thesemineral oil based cutting fluids exhibit generally good qualities ofcooling and lubrication, they have several attendant disadvantages,including instability to bacterial attach and poor corrosion inhibition.For these reasons, cutting fluid formulations have been developed whichemploy synthetic, rather than mineral oil bases. Many improvements overthe mineral oil compositions are realized in the synthetic cuttingfluids, such as stability to bacterial decomposition and improved rustinhibition. The synthetic base lubricants heretofore developed, however,have not satisfied all the requirements necessary to provide a generallywell-balanced, efficient cutting fluid. For, whereas one may exhibitgenerally good lubricating and cooling qualities, it may have anobjectionable odor, be irritating to the nose and throat of the operatoror cause foaming; which obscures the operator's view of the materialbeing worked, another may have an agreeable odor, or none at all, and benonirritating and safe for the operator, yet fail to produce a goodfinished surface on the work piece, the finish perhaps being repletewith microscopic ridges, grooves and surface cracks.

it is an object of this invention to provide an aqueous coo lant formetal-working which is improved with respect to bacterially promoted orchemically caused odor, germ-forming tendency, irritation of the skin,clarity and ash content. It is a further object of this invention toprovide novel emulsifying agents for use in aqueous metal-workinglubricating compositions containing synthetic lubricants.

ln copending application, Ser. No. 7l2,965, filed Mar. 18, I965, in thenames of Howard D. Gower, Bob G. Gower and David W. Young, there isdisclosed a metal-working coolant which comprises a minor, effectiveamount of an extreme pressure lubricating agent and an amine salt of acopolymer resin, which resin can have a styrene to maleic anhydridewhole ratio of about lzl to 5:1. The resin can also be an ester of thesepolymers, being up to 100 percent half-esters, esterifred with a memberselected from the group consisting of alcohols and capped glycols havingthe structure where R and R are aliphatic hydrocarbon radicals of abouttwo to six carbon atoms, the total number of carbon atoms in R and asingle R is less than about seven and x is from to about 10. Thesecoolants have been found to be advantageous.

In accordance with the present invention it has been found that cuttingand abrading, including tapping, and other machining operations, of ahigh degree of efficiency and are obtained when conducted in thepresence of aqueous solutions of water-soluble alkali metal, ammonium oramine salts of styrene-maleic anhydride copolymer esters, whichcopolymers are esterfied with both a fatty alcohol having from 10 to 22carbon atoms and a lower alkoxy polyethylene glycol. In addition it hasbeen found that these water-soluble salts are particularly effective asemulsifiers in aqueous lubricating compositions containing extremepressure agents. The salts of this invention have been found to possesslong term stability and good shelflife in aqueous lubricatingcompositions.

The copolymer ester can be made by the esterification of astyrene-maleic anhydride copolymer with both a fatty alcohol containingabout 10 to 22 carbon atoms, preferably about [6 to l8 carbon atoms, anda lower alkoxy, e.g., of one to four carbon atoms, polyethylene glycolof an average molecular weight of about 200 to 750, preferably about 500to 700. The fatty alcohol can be saturated, such as octadecanol, orolefini cally unsaturated, such as oleyl alcohol. isomers of thesealcohols, such as isostearyl alcohol are also suitable. The lower alkoxypolyethylene glycol is preferably a methoxy polyethylene glycol. Thefatty alcohol and glycol are reacted in proportions such as to provide afatty alcohol to glycol mole ratio of about 0.3/1 to l.l/l preferablyabout 0.75/1 to III.

A slight excess of the glycol is desirable since water solubility isthereby increased. The mole ratio of fatty alcohol to anhydrideequivalents in the copolymer esters is from about 0.25 to 0.5,preferably 0.4 to 0.5. The mole ratio of glycol to anhydride equivalentsis from about 0.5 to 1.0, preferably 0.5 to 0.75. The polymer has estergroups from both the lower alkoxy polyethylene glycol and the fattyalcohol on the same polymer molecules. The ester is thus distinct from amixture of the corresponding polymers each being esterified with onlyone of the aforesaid glycol and fatty alcohol. The polymer can beesterified with a mixture of the alcohol and lower alkoxy polyethyleneglycol or it can be esterified sequentially with either the alcohol orglycol followed by esterifrcation with the other. In either case, it isimportant that the polymer contains both the alcohol and glycol groupsand not a mixture of ester polymers which are separately and singlyesterified with the alcohol or glycol.

Preparation of the styrene-maleic anhydride polymer components of thecomposition of the present invention can be made by known methods; forexample, it can be made in accordance with the teachings of US. Pat. No.3,342,787, issued Sept. l9, i967. Thus, styrene and maleic anhydride canbe first polymerized, for instance, by solution polymerization where themonomers are polymerized in a suitable solvent employing as apolymerization catalyst a free-radical catalyst, such as a peroxide,preferably benzoyl peroxide, dicumyl peroxide or an alkyl peroxydicarbonate, at a temperature of about 75 to 300 C. or more. Suitablesolvents are aromatics such as cumene, p-cymene, xylene, toluene, etc.Other suitable solvents are the ketones, such as methylethyl ketone. Apreferred manner of carrying out the polymerization is by what is knownas incremental feed addition. By this method the monomers and catalystare first dissolved in a portion of the solvent in which thepolymerization is to be conducted and the resulting solution fed inincrements into a reactor containing solvent heated to reactiontemperature, usually the reflux temperature of the mixture.

When an aromatic hydrocarbon is employed as the solvent for thepolymerization the formation of the copolymer gives a heterogeneoussystem, the polymer layer being the heavier layer and recoverable bymerely decanting the upper aromatic solvent layer and drying. On theother hand, when a ketone is.

the solvent, the formed copolymer is usually soluble in the solventmedia so that recovery of the product necessitates a solvent strippingoperation. The polymer contains a molar ratio of styrene to maleicanhydride of from about H to about 5:1 and has an average molecularweight, prior to esterification of about 600 to 5,000, preferably about800 to about 2,500.

The esterification product of the present invention can be formed byesterifying the styrene-maleic anhydride polymer with a lower alkoxypolyethylene glycol, preferably methoxy polyethylene glycol, of anaverage molecular weight of about 200 to 750, preferably about 500 to700, in the presence of a fatty alcohol containing to 22 carbon atoms,preferably about 16 to 18 carbon atoms. The esterification can becarried out at any convenient temperatures, e.g., about 100 to 220 C.,preferably about 140 to [90 C. Although no catalyst is necessary, theesterification can be carried out in the presence of a catalytic amountof, for instance, a fatty acid metal salt, preferably an alkali metalsalt. The alcohol and glycol can be present, as noted above, in a moleratio of about from 0.3:1 to l.l:l, preferably about 0.75:1 to lzl. Apreferred product is prepared by the reaction of approximately oneanhydride equivalent weight of a lzl styrene-maleic anhydride copolymer(average molecular weight of l,500) 0.5 moles medroxy polyethyleneglycol (average molecular weight of about 550) and 0.5 moles of stearylalcohol l-octadencanol). The polymer is about 4 to I50 percent,preferably about 40 to 120 percent, half-esterified with the totalmethoxy polyethylene glycol and alkanol. The water-soluble salts of thisinvention can be formed by reacting an alkali metal, ammonia orwater-soluble amine with the styrene-maleic anhydride or its partialester to react with free carboxyl groups present in the partial ester.

The water-soluble, salt-forming amines having boiling points above about200 C. can be employed in the present invention to form the amine saltsof the styrene-maleic anhydride copolymer partial ester. Preferredamines are tertiary amines such as, for example, tributylamine andtrifurfurylamine; and hydroxyl lower alkyl amines such as, for example,diethanolamines and triethanolamines. Glycol amines or capped glycolamines of molecular weights up to about 5,000 are also suitable. Theethanolamines are preferred.

A preferred method of reacting the amine and the copolymer is to firstdissolve the amine in the water and then add the copolymer while keepingthe temperature below about 140 F. to minimize evaporation. Sufficientagitation may be employed to insure complete formulation. Similarly, analkali metal or ammonium salt can be prepared by means known in the art.

The compositions of this invention can contain from about 0.l to 50,preferably from about 0.5 to l0, weight percent of the alkali metal,ammonia or amine component, from about 2 to 40, preferably from about 4to 20, weight percent of the styrene-maleic anhydride copolymer esterand from about 20 to 95, preferably from about 70 to 90, weight percentwater. The amount of alkali metal, ammonia or amine present is oftensufficient to neutralize the compositions or make them basic. Thecompositions of this invention also contain minor, effective amounts ofwater-soluble extreme pressure lubricat ing agents such as water-solubleamine salts of organic phosphate ester acids or of fatty acids of aboutl2 to 20 carbon atoms, for example, triethanolamine oleate,diethanolamine oleate, and similar salts of the various watersolubleamines used to form the water-soluble salts of styrenemaleic anhydridepolymers of this invention. These extreme pressure agents are generallyeffective in the composition of the present invention when employed inminor amounts, for instance, about 2 to weight percent, preferably about4 to it) weight percent, of the solution ofalkali metal, ammonia oramine; styrene-maleic anhydride copolymer ester and water Where the sameamine is employed to form the styrene-maleic anhydride salt as is usedto form the salt of the fatty acid, the fatty acid may be added directlyalong with the styrenemaleic anhydride partial ester to the aqueoussolution containing an amount of the amine in excess of that needed toform the styrene-maleic saltv The organic phosphate ester acids whichmay be employed as E.P agents in the present invention can be, forinstance, primary. secondary, or tertiary esters of phosphoric acid anda hydroxyl compound which can be exemplified by the ky alkanols,phenols, including the alkyhmonophenols, and monoalkyi, monoarylandmonoarylalkyl-esters of poltal kylene glycols. These phosphate compoundspreferably include those corresponding to the following general formula:

wherein R is a hydrocarbon radical having about one to 30, preferablyeight to l8, carbon atoms, 1: equals 2 to 10, preferably 2, y is 0 to20, preferably 2 to 8, and n is l to 2. The R groups can be alkyl, arylor mixed alkyl-aryl radicals.

These phosphate ester acids of this invention may be oil orwater-soluble, depending to a degree on the vaiue of y, although thesize of R and 1 may also be factors in determining solubility. Generallyoil-solubility tends to increase with larger values of R and .1: whilewater solubility increases with larger values of y, for example, aboveabout y==8 or l0 the esters tend to be watersoluble while below 5 theycan generally be oilsoluble. in any event, where the ester acids arewater-insoluble, salt'fonning amine, for example, triethanolamine, canbe included in the composition to react with and solubilize the esteracid. At least about i part by weight of amine per part of phosphateester acid can often be required to solubilize the ester acid in water.

Phosphate ester acids useful as the extreme pressure lubricant componentin the present invention include, for example, mono and di-octyl andoxo-decyl phosphates, mixtures of monoand dilauryl phosphate, laurylpolyethylenoxy phosphate esters, nonylphenylpolyethyleneoxy phosphateesters and the like. Methods of preparation of the phospahte ester acidssuitable for use in the composition of the present invention appear inabundance in the prior art. US. Pat. No. 3,033,889 to Chiddix et al.(herein incorporated by reference), for example, discloses thepreparation of phosphate esters of branched chain (Oxo) alcoholssuitable as to the phosphate lubricant in the present invention.Similarly, the preparation of suitable alkyl, aryl and mixedalkaryl-alkyl polyethyleneoxy phosphate ester acids is described in U.S.Pat. No. 3,004,056 to Nunn et al. and No. 3,004,057 to Nunn, bothpatents being herein incorporated by reference.

In addition to the water-soluble salt of the copolymer, the E.P. agent,and the water, the composition of this invention may also containvarious additives such as, for example, about I to [0 weight percent ofan anti-foaming agent such as hexadecyi alcohol, or other monohydricalcohols of from about six to 20 carbon atoms; about 2- l0 weightpercent, preferably about 3-9 weight percent, boric acid or othersuitable boron compound, such as borax, which forms boric acid onhydration, or a mixture of such compounds with low molecular weightamines such as methylethyl amine or tributyl amine and sodium nitritewhich can provide protection against rust. Water-soluble glycols, suchas hexylene glycols and polyethylene glycols of up to about 5,000molecular weight, or capped glycols and polyglycols, such as diethyleneglycol monoethyl ether, have been found to prevent film formation andtackiness on the machinery or product and improve settling of finesolids for recirculation of fluid and may be employed in amounts up toabout 30, preferably about l0 to 25, weight percent. Small amounts ofwater-soluble silicones may be added an anti-foaming agents and sodiumnitrite may also be added as a corrosion inhibitor. it is preferred thatthe lubricant composition have a viscosity of below about poise at 2 5 Cin use, the lubricating composition of this invention may be dilutedwith water, for instance, to a concentration of 1 part by weight of thecutting oil composition to about l to 100, preferably 5 to 50, parts byweight ofwater.

The invention shall be further described in the following examplesEXAMPLE l A siyrene-maleic anhydride copolymer ester was prepared byreacting approximately one anhydride equivalent weight followingresults:

Test Result 1: carbon 64.61 70 hydrogen 8.78 k oxygen 27.09 Acid Number62.4

This product was assigned sample designation "A".

A second reaction was performed in like manner with one anhydrideequivalent of a styrene-maleic anhydride copolymer of an averagemolecular weight of 1,500, an acid number of 490 and a styrene to maleicanhydride molar ratio of 1:1 with 1 mole (350 g.) of a methoxypolyethylene glycol of an average molecular weight of 350. The productanalyzed Test Result 1: carbon 51.7 i hydrogen 7.6 in oxygen 31.82 AcidNumber 174.3

This product was assigned sample designation B".

Samples A and B were dissolved in water to make percent aqueoussolutions and these solutions were further reacted with sufficienttriethanolamine to make solutions of a pH of 7.0. The stoichometrlcamount of triethanolamlne to neutralize Sample A is about 16.6 grams per100 grams of the styrene maleic anhydride resin ester while this amountfor Sample B is about 46.3 grams per 100 grams of the resin ester. Thesesolutions were then subjected to tapping torque tests on various metals.A commercial tapping fluid, designated Composition X, was also evaluatedin the tests. Results of the tests are shown in Table 1. As can be seenfrom these results, Sample A (a composition containing the mixing esterof this invention) yielded lower torque values than the Sample Bmonoester on every metal tested. From prior testing, it is apparent thattapping torque data can be related to other metal-working operationssuch as cutting and abrading, including grinding, honing, etc. Theinvention as herein disclosed can thus be applicable to a variety ofother industrial applications.

TABLE I Tapping Torque Test Tap 60% Express Metal 8620 9310 copper 2024steel steel aluminum Sample 110 H,O dilution In. Lbs. A 300 250 408 184B 424 272 414 349 Tapping I21 400 350 120 composition EXAMPLE 11 About100 g. of the 10 percent aqueous solution of Sample A from Example 1 iscombined with sufficient triethanolarnine to make a pH of 7.0 in thesame manner as in Example I. About 8 g. of an organic phosphate esteracid extreme pressure lubricating agent is added to the resultingsolution to yield a composition containing about 7.3 weight percentlubricating agent. The organic phosphate ester acid is a mixture ofapproximately equal amounts of primary and secondary phosphate esters ofthe oxyethylene ether of of 0x0 tridecyl alcohol, the ether containingan average of 5 oxyethylene groups. The solution is subjected to tappingtorque tests on various metals with similar results as shown per SampleA in Example 1.

It is claimed:

1. A lubricating composition comprising an aqueous solution of an alkalimetal, ammonium or water-soluble amine salt of a styrene-maleicanhydride copolymer ester and a minor, effective amount of an extremepressure lubricating agent, wherein the polymer has a styrene to maleicanhydride molar ratio of about 1:1 to 5:1 and an unesterified molecularweight of about 600 to 5,000, esterified with both of (A) a fattyalcohol containing from about 10 to 22 carbon atoms; and (B) a loweralkoxy polyethylene glycol wherein the alkoxy group contains one to fourcarbon atoms and having an average molecular weight of about 200 to 750,said (A) and (B) being in a mole ratio of from about 0.3 to 1.1:1, andwherein about 4 to 150 percent of the total number of carboxyl carbonatoms of the polymer are half-esterified with (A) and (B).

2. The composition of claim 1 wherein the polymer has an unesterifiedmolecular weight of about 800 to 2,500.

3. The composition of claim 2 wherein the (A) fatty alcohol containsabout 16 to 18 carbon atoms.

4. The composition of claim 3 wherein the (B) lower alkoxy polyethyleneglycol has an average molecular weight of about 500 to 700.

5. The composition of claim 4 wherein the said (A) and (B) are presentin a mole ratio of 0.75:1 to 1: 1.

6. The composition of claim 5 wherein about 4 to 120 percent of thetotal number of carboxyl carbon atoms of the polymer are half-esterifiedwith (A) and (B).

7. The composition of claim 6 wherein the amine salt is of awater-soluble amine having a boiling point above about 200 8. Thecomposition of claim 7 wherein the extreme pressure agent is amine saltof a fatty acid of from 12 to 20 carbon atoms.

9. The composition of claim 7 wherein the extreme pressure agent is aphosphate ester acid.

10. The composition ofclaim 1 wherein the copolymer ester salt is of awater-soluble salt-forming amine having a boiling point above about 200C.

11. The composition of claim 10 wherein the amine is triethanolamine.

12. The composition of claim 11 wherein the polymer has a styrene tomaleic anhydride ratio of about 1:1 and an average molecular weight,prior to esterification, of about 800 to 2,500.

13. The composition of claim 12 wherein the (A) fatty alcohol contains16 to 18 carbon atoms.

14. The composition of claim 13 wherein the lower alkoxy polyethyleneglycol is methoxy polyethylene glycol.

15. The composition of claim 14 wherein the mole ratio of (A) to (B) isfrom about 0.75:1 to 1:].

16. The composition of claim 1 which contains about 2 to 15 weightpercent of a water-soluble extreme pressure agent based on the weight ofthe solution of the alkali metal, ammonia or amine, copolymer ester saltand water.

17. The composition of claim 16 wherein the extreme pressure agent is anamine salt of a fatty acid of from 12 to 20 carbon atoms.

18. The composition of claim 16 wherein the extreme pressure agent is aphosphate ester acid.

19. The composition ofclaim 1 comprising from about 20 to 95 weightpercent of water based on the total weight of said salt and water, saidcopolymer ester component of said salt being from about 2 to 40 weightpercent of the total composition and said alkali metal, ammonium orwater soluble amine component of said salt being from about 0.01 to 50weight percent of the total composition.

20. The composition of claim 19 comprising from about 70 to weightpercent of water based on the total weight of said salt and water. saidcopolymer ester component of said salt being from about 4 to 20 weightpercent of the total composition and said alkali metal, ammonium orwater-soluble amine component of said salt being from about 0.5 to 10percent of the total composition.

: t n: e t 5

2. The composition of claim 1 wherein the polymer has an unesterifiedmolecular weight of about 800 to 2,500.
 3. The composition of claim 2wherein the (A) fAtty alcohol contains about 16 to 18 carbon atoms. 4.The composition of claim 3 wherein the (B) lower alkoxy polyethyleneglycol has an average molecular weight of about 500 to
 700. 5. Thecomposition of claim 4 wherein the said (A) and (B) are present in amole ratio of 0.75:1 to 1:1.
 6. The composition of claim 5 wherein about4 to 120 percent of the total number of carboxyl carbon atoms of thepolymer are half-esterified with (A) and (B).
 7. The composition ofclaim 6 wherein the amine salt is of a water-soluble amine having aboiling point above about 200* C.
 8. The composition of claim 7 whereinthe extreme pressure agent is amine salt of a fatty acid of from 12 to20 carbon atoms.
 9. The composition of claim 7 wherein the extremepressure agent is a phosphate ester acid.
 10. The composition of claim 1wherein the copolymer ester salt is of a water-soluble salt-formingamine having a boiling point above about 200* C.
 11. The composition ofclaim 10 wherein the amine is triethanolamine.
 12. The composition ofclaim 11 wherein the polymer has a styrene to maleic anhydride ratio ofabout 1:1 and an average molecular weight, prior to esterification, ofabout 800 to 2,500.
 13. The composition of claim 12 wherein the (A)fatty alcohol contains 16 to 18 carbon atoms.
 14. The composition ofclaim 13 wherein the lower alkoxy polyethylene glycol is methoxypolyethylene glycol.
 15. The composition of claim 14 wherein the moleratio of (A) to (B) is from about 0.75:1 to 1:1.
 16. The composition ofclaim 1 which contains about 2 to 15 weight percent of a water-solubleextreme pressure agent based on the weight of the solution of the alkalimetal, ammonia or amine, copolymer ester salt and water.
 17. Thecomposition of claim 16 wherein the extreme pressure agent is an aminesalt of a fatty acid of from 12 to 20 carbon atoms.
 18. The compositionof claim 16 wherein the extreme pressure agent is a phosphate esteracid.
 19. The composition of claim 1 comprising from about 20 to 95weight percent of water based on the total weight of said salt andwater, said copolymer ester component of said salt being from about 2 to40 weight percent of the total composition and said alkali metal,ammonium or water soluble amine component of said salt being from about0.01 to 50 weight percent of the total composition.
 20. The compositionof claim 19 comprising from about 70 to 90 weight percent of water basedon the total weight of said salt and water, said copolymer estercomponent of said salt being from about 4 to 20 weight percent of thetotal composition and said alkali metal, ammonium or water-soluble aminecomponent of said salt being from about 0.5 to 10 percent of the totalcomposition.